Touch screen system and method of driving the same

Abstract

A touch screen system includes a touch screen panel including first lines, second lines crossing the first lines, a plurality of sensing cells formed at the crossing regions between the first lines and the second lines, a driving circuit for sequentially applying a driving signal to the first lines, a first sensing circuit for receiving capacitance change information sensed by the first lines, and generating a first sensing signal corresponding to the capacitance change information, a selecting unit for selectively coupling the first lines to the driving circuit or the first sensing circuit, a second sensing circuit for receiving the capacitance change information sensed by the sensing cells from the second lines and generating a second sensing signal corresponding to the capacitance change information, and a processing unit for receiving a sensing signal from the first sensing circuit and / or the second sensing circuit and determining a detected touch position.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims priority to and the benefit of Korean Patent Application No. 10-2011-0035729, filed on Apr. 18, 2011, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.BACKGROUND[0002]1. Field[0003]Aspects of embodiments according to the present invention relate to a touch screen system, and more particularly, to a touch screen system capable of multi-touch recognition and a method of driving the same.[0004]2. Description of Related Art[0005]A touch screen panel is an input device capable of selecting the indication content displayed on the screen of an image display device, by using a human hand or an object in order to input the command of a user.[0006]Therefore, the touch screen panel is provided on the front face of the image display device to convert a contact position selected by the human hand or the object into an electrical signal. Therefore, the instruction content...

AI Technical Summary

Benefits of technology

The present invention is about a touch screen system that can recognize touch using both fingers and an active stylus. The system includes a touch screen panel with first and second lines, sensing cells, and a driving circuit. The driving circuit sequentially applies a driving signal to the first lines, while the first sensing circuit samples the capacitance change information and generates a sensing signal. The second lines are then selected and coupled to either the driving circuit or the sensing circuit, and the second sensing circuit samples the capacitance change information from the second lines and generates a sensing signal. The system can also include an active stylus that generates an electric field signal at a set frequency. The invention allows for simultaneous touch recognition by both fingers and the active stylus, and also allows for separate processing of touch recognition by the finger and the active stylus for various multi-touch recognitions. The frequency of the electric field signal emitted by the active stylus is set to correspond to the sampling signal frequency of the sensing circuit so as to clearly separate noise signals and perform accurate touch recognition.

Problems solved by technology

However, in the case of the above method, it is difficult to realize minute contact position recognition through the contact performed by the finger.

However, in the case of a passive stylus, the change in the capacitances generated by the sensing cells positioned on the contact surface is extremely slight so that it is difficult to detect a contact position.

In the case of an active stylus in which an electric field is generated by the active stylus, not only the sensing cell (node) of the touch screen panel in the actual contact position, but also the other sensing cells (nodes) coupled to sensing lines are affected by the generated electric field so that it is not possible or very difficult to grasp the contact position.

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